1. Field of the Invention
The present invention relates to a thin-film magnetic head which is applied to a magnetic disk unit or the like for moving relative to a magnetic recording medium and writing or reading information in or from the medium.
2. Description of the Background Art
A thin-film magnetic head, which has excellent frequency characteristics and is capable of high-density recording through refinement of the track width and the bit length, is employed as a magnetic head for recording and reproduction in a magnetic disk unit or the like.
Such a thin-film magnetic head is generally provided with protective layers for holding and protecting a head part. The material from which such protective layers are generally prepared is Al.sub.2 O.sub.3. When a reproducing head and a recording head are provided independently of each other, a separation layer is provided between these heads. The material for such a separation layer is also generally prepared from Al.sub.2 O.sub.3.
However, the hardness of Al.sub.2 O.sub.3 is about 1000 to 2000 kg/mm.sup.2, and hence the head part is disadvantageously damaged in grinding. In order to protect the head further, each protective layer must have a thickness of about 30 to 40 .mu.m. Thus, a process of forming the protective layers disadvantageously requires a long time.